Guidelines Call Botulinum Toxin Ineffective for Headache

Action Points

Explain to interested patients that these recommendations are derived from the available evidence.

Point out that Botox is approved for the treatment of strabismus, blepharospasm, cervical dystonia, axillary hyperhidrosis, and glabellar lines; Myobloc is approved for cervical dystonia.

NEW YORK, May 6 -- Botulinum toxin injections (Botox, Myobloc) should be shunned for relief of episodic migraine and chronic tension headaches, according to guidelines just issued by the American Academy of Neurology.

Botulinum toxin should be reserved as a treatment option for cervical dystonia, spasticity, and excessive sweating, recommended David M. Simpson, M.D., of Mount Sinai here, and colleagues, in a series of three academy guideline statements in the May 6 issue of Neurology.

Evidence from their systematic reviews, albeit less conclusive, also supported use of the injections for hemifacial spasm, blepharospasm, some voice disorders, focal limb dystonias, essential tremor, and some spastic bladder disorders.

The negative take on use in headache "may surprise many people," Dr. Simpson said. Early evidence was promising, but studies accumulating over the past several years have shown it to be no better than placebo for this off-label use, he said.

Nevertheless, "many people may continue to both prescribe and use botulinum toxin for headache because they may feel that they're responding," Dr. Simpson said. "In fact, individual patients may respond."

Even the best clinical trials cannot reflect the precise situation for each patient, he said.

The guidelines offer clinicians guidance that may be particularly useful in light of recent concerns over the use of botulinum toxin, Dr. Simpson said.

Then in March, Allergan, the maker of Botox and Botox Cosmetic, announced that the FDA was investigating the company's alleged off-label promotion of Botox for the treatment of headache.

And in April, an animal study reported in the Journal of Neuroscience showed that botulinum toxin from intramuscular injections travels from neuron to neuron to reach the brain, which it had not been thought to do.

"These are not trivial procedures and should be given careful consideration," commented David M. Sherry, Ph.D., of the University of Oklahoma Health Science Center in Oklahoma City, who was not involved in the study.

However, Dr. Simpson cautioned against over-interpreting the animal study because "none of us know yet what the implications of those animal data are for humans." Dr. Sherry also noted that the drugs are "in such wide use now, particularly cosmetically, that if there were really severe problems with it we would already be seeing those effects."

Because the field has been moving so quickly since the last academy guidelines on botulinum toxin use were published about 10 years ago, Dr. Simpson's group undertook a full systematic review for approved and common off-label uses.

On the basis of four studies each in episodic migraine and chronic tension-type headache, the researchers concluded botulinum toxin "is probably ineffective."

However, studies presented conflicting evidence for use of these injections in chronic daily headache, mainly transformed migraine, which did not allow any recommendation.

"It is possible that underdosing and suboptimal muscle selection may account for some of the reported failures in studies of botulinum toxin in headache," the guidelines concluded. Dr. Simpson added that these conclusions may change as better evidence emerges, particularly from ongoing phase III studies with botulinum toxin for treatment of headache.

Other recommendations included:

Botulinum neurotoxin should be offered as a treatment option for the treatment of spasticity in adults and children, with the best pediatric evidence for spastic equinus and adductor spasticity in cerebral palsy.

The agents should be offered as an option for treatment of axillary hyperhidrosis and detrusor overactivity with the best level of evidence.

These injections should be offered as a treatment option for treatment of cervical dystonia with the best level of evidence.

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